Kylo not killing Luke didn't bother me, but I will say if Snoke's "supremeness" was given more weight, that rub might have been all he needed.
As far as the Casino, as I've stated, the whole subplot is a joke. We get Maz thrown in cuz "remember her?" in a very campy cameo. Also, if this happens after TFA, I think it was a missed op to not address Han's passing since they apparently were very good friends. Anywho, she says only one guy can crack the code - THE MASTER CODEBREAKER....
but it turns out there's more than one guy that can crack the code, and they really don't make clear if he's the master codebreaker or not. Just a lot of huge flaws within that whole narrative. From beginning, to end, to who's included. Just, ugh...
The timing of everything seems off, too? It's not made clear if Rey's training is taking place the same time as the "Space's Slowest Chase". We know Rey spends several nights at Ahch-to, but it cuts between the chase which takes place not long after TFA and is within a 16-18 hour period of time.